Conventional bottle caps or closures for carbonated beverages have included cork and plastic liners and metal fluted caps which are crimped around the radius lip of a glass bottle. Recent bottle closures have included a plastic or metal cap with a frangible ring which interlocks with the bottle neck to be held in axially fixed position while an upper cap portion is unscrewed. U.S. Pat. No. 5,564,582 describes such a frangible ring tamper-evident closures.
A closure including an inner disc having applied thereon a container-engaging liner element and an overlying outer screw cap are known. In this type of closure, the liner element is secured to the lower face of the disc for engagement with a top of an associated container. The outer plastic cap includes screw threads which are advanced onto respective formations of the container which presses the disc and liner into sealing engagement with the container.
It is also known, in general, to provide one or more breakable or frangible elements arranged in a top wall of the outer closure cap. Such structures are disclosed, for example, in published PCT Application WO 94/29186.
The need exists for a closure that can be inexpensively manufactured, applied to both pressurized and partially evacuated containers, and can provide an effective seal by closure rotation, and tamper evidence by a subsequent counter-rotation. The closure needs to maintain its effective seal even with the imposition and release of heavy top loading, such as that experienced in storage and shipment.
The need exists for a closure which has a high degree of reliability against liner failure and displacement, tamper evidence accuracy, and seal integrity after repeated reclosures. The need exists for a tamper evident closure having clear indication of prior closure removal. The need exists for a tamperevident closure which is difficult to remove without triggering indication of prior removal.